Paper sheet break detection apparatus

ABSTRACT

A paper sheet break detection unit having a light source which emits light to a card deformed by the pressure of flanges of front- and back-side lower rollers, a control unit which judges that a card includes a break, based on the reception of light by a light-receiving sensor, and a moving mechanism which moves the flanges of upper and lower rollers along a conveying surface in a direction orthogonal to a direction of conveying a card K, by moving the upper and lower rollers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromprior Japanese Patent Application No. 2005-306980, filed Oct. 21, 2005,the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a paper sheet break detection unit,which detects a break in a paper sheet, for example, paper currency.

2. Description of the Related Art

A unit shown in FIG. 20 is well known as such a detection unit.

Namely, a reference numeral 111 denotes a conveying path. Upper-sideconveying rollers 112 a and 112 b are provided at a predeterminedinterval on the upper side of the conveying path 111, and lower-sideconveying rollers 113 a and 113 b are provided on the lower side at apredetermined interval. An upper conveying belt 114 a is extended overthe upper-side conveying rollers 112 a and 112 b, and a lower-sideconveying belt 114 b is extended over the lower-side conveying rollers113 a and 113 b. These upper and lower conveying belts 114 a and 114 bhold and convey a paper sheet.

Between the upper-side conveying rollers 112 a and 112 b, a roller 115having a flange 115 f and a projection plate 116 are provided. Theroller 115 is placed with the lower end side of the flange 115 projecteddownward the conveying path 111, and the projection plate 116 is placedwith the upper-end side projected upward the conveying path 111. A lightsource 118 is provided under the projection plate 116. A light-receivingsensor 119, which receives the light emitted from the light source 118,is provided between the roller 115 and upper-side conveying roller 112b.

When a paper sheet is conveyed along the direction of the arrow andreaches the projection plate 16, the paper sheet is pressed upward bythe projection plate 16, and pressed downward by the flange 115 f whenreaching the roller 15. Therefore, if there is a break in a paper sheet,the break is pressed and opened, and the light emitted from the lightsource 118 is received by the light-receiving sensor 119, passingthrough the break. When the light is received, it is judged that thepaper sheet has a break. If the light is not received, it is judged thatthe paper sheet does not have a break. (Refer to Jpn. Pat. Appln. KOKAIPublication No. 2000-268225, for example.)

However, conventionally, as the projection plate 116 is fixedlyprovided, there is a drawback that when a paper sheet is conveyed athigh speed to the projection plate 116, the projection plate 116 isworn, and a break of an easy-to-tear paper sheet is not opened.

Further, as the roller 115 and projection plate 116 are provided atfixed positions, when a different size paper sheet is conveyed, theflange 115 f of roller 115 and the projection plate 16 may come off thebreak of the paper sheet, and the break cannot be detected.

Further, when detecting a break in the same size paper sheet, it isimpossible to adjust so that only a break longer than a predeterminedlength is detected. Therefore, there is a problem that even a negligiblebreak is detected.

BRIEF SUMMARY OF THE INVENTION

The present invention has been made in the above-mentionedcircumstances. Accordingly, it is an object of the invention to providea paper sheet break detection unit, which reliably detects a break evenin a different size paper sheet.

According to an aspect of the invention, there is provided a paper sheetbreak detection unit comprising a conveying unit which conveys a papersheet along a conveying surface; a first pressing unit which presses oneside of the paper sheet conveyed by the conveying unit in a firstdirection orthogonal to the conveying surface; a second pressing unitwhich is provided in proximity to the first pressing unit, and pressesthe other side of the paper sheet conveyed by the conveying unit in asecond direction reverse to the first direction; a light-emitting unitwhich emits light to the paper sheet deformed by the pressure of thefirst and second pressing units; a light-receiving unit which receivesthe light illuminated from the light-emitting unit; a judgment unitwhich judges whether the paper sheet includes a break based on thereception of the light by the light-receiving unit; and a movingmechanism which moves the first and second pressing units along theconveying surface in a direction orthogonal to a direction of conveyingthe paper sheet.

According to another aspect of the invention, a paper sheet breakdetection unit is capable of detecting securely a break in a differentsize paper sheet or in an easy-to-tear paper sheet, and capable ofdetecting only a break of desired length when detecting a break in thesame size paper sheet.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a schematic block diagram showing the configuration of a papersheet processing system according to a first embodiment of theinvention;

FIG. 2 is a front view of a paper sheet break detection unitincorporated in the paper sheet processing system of FIG. 1;

FIG. 3 is a top plane view of the paper sheet break detection unit ofFIG. 2;

FIG. 4 is a longitudinal sectional view of the paper sheet breakdetection unit of FIG. 2;

FIG. 5 is a block diagram showing a control system of the paper sheetprocessing system of FIG. 1;

FIG. 6 is a front view showing the state that a card having no break issent to the paper sheet break detection unit of FIG. 2;

FIG. 7 is a longitudinal sectional view showing the state that a cardhaving no break is sent to the paper sheet break detection unit of FIG.2;

FIG. 8 is a perspective view of a card having no break sent to the papersheet break detection unit of FIG. 2;

FIG. 9 is a perspective view of a card having a break sent to the papersheet break detection unit of FIG. 2;

FIG. 10 is a front view showing the state that the card of FIG. 9 issent to the paper sheet break detection unit of FIG. 2;

FIG. 11 is a longitudinal section view showing the state that the cardof FIG. 9 is sent to the paper sheet break detection unit of FIG. 2;

FIG. 12 is a view showing a sensor signal when the paper sheet breakdetection unit of FIG. 2 does not detect a break in a card;

FIG. 13 is a view showing a sensor signal when the paper sheet breakdetection unit of FIG. 2 detects a break in a card;

FIG. 14 is a view showing the state that a pair of upper-side rollers ofthe paper sheet break detection unit of FIG. 2 are moved in thedirection of coming close to each other, and the state that a pair oflower-side rollers are moved in the direction of coming close to eachother;

FIG. 15 is a view showing the state that a pair of upper-side rollers ofthe paper sheet break detection unit of FIG. 2 are moved in thedirection of separating from each other, and the state that a pair oflower-side rollers are moved in the direction of separating from eachother;

FIG. 16 is a view showing the state that when the paper sheet breakdetection unit of FIG. 2 detects a break in the same size card, pairs ofupper-side and lower-side rollers are moved to the position to open abreak;

FIG. 17 is a view showing the state that when the paper sheet breakdetection unit of FIG. 2 detects a break in the same size card, pairs ofupper-side and lower-side rollers are moved to the position not to opena break shorter than a predetermined length;

FIG. 18 shows a paper sheet break detection unit according to a secondembodiment of the invention, and is a view showing the state that a pairof upper-side air nozzles are moved in the direction of coming close toeach other, and a pair of lower-side air nozzles are moved in thedirection of coming close to each other;

FIG. 19 is a view showing that a pair of upper-side air nozzles aremoved in the direction of separating from each other, and a pair oflower-side air nozzles are moved in the direction of separating fromeach other; and

FIG. 20 is a front view of a conventional card break detection unit.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention will be explained hereinafter withreference to the accompanying drawings.

Embodiment 1

FIG. 1 is a block diagram showing the configuration of a paper sheetprocessing system according to a first embodiment of the invention.

In FIG. 1, a reference numeral 1 denotes a take-out unit to take outstacked cards as paper sheets one by one. A card taken out by thetake-out unit 1 is conveyed along a conveying path. In the conveyingpath, a detection unit 2 is provided to detect a break formed in a card.In the downstream side of the card conveying direction of the detectionunit 2, a branch gate 3 is provided to guide a card with no breakdetected to a first direction and a card having a break detected to asecond direction. A first stack 4 to stack a card with no break detectedis provided in the first direction, a second stack 5 to stack a cardhaving a break detected is provided in the second direction.

FIG. 2 is a front view of the detection unit 2. FIG. 3 is a top planeview of the detection unit. FIG. 4 is a longitudinal sectional view ofthe detection unit.

In FIG. 2, a reference numeral 11 denotes a conveying path. In the upperside of the conveying path 11, front- and back-side upper conveyingrollers 12 a and 12 a′ are provided with a predetermined space takentherebetween in the direction orthogonal to the card conveyingdirection. In the lower side of the conveying path 11, front- andback-side lower conveying rollers 13 a and 13 a′ are provided with apredetermined space taken therebetween in the direction orthogonal tothe card conveying direction.

In the downstream side of the card conveying direction of the front- andback-side upper conveying rollers 12 a and 12 a′, and front- andback-side upper conveying rollers 12 b and 12 b′ are provided. In thedownstream side of the card conveying direction of the front- andback-side lower conveying rollers 13 a and 13 a′, and front- andback-side lower conveying rollers 13 b and 13 b′ are provided.

An upper conveying belt 14 a is extended over the front-side upperconveying rollers 12 a and 12 b, and an upper conveying belt 14 c isextended over the back-side upper conveying rollers 12 a′ and 12 b′. Alower conveying belt 14 b is extended over the front-side lowerconveying rollers 13 a and 13 b, and a lower conveying belt 14 d isextended over the back-side lower conveying rollers 13 a′ and 13 b′. Theconveying unit is composed of the upper conveying belt 14 a/14 c andlower conveying belt 14 b/14 d. In the card take-in side of thedetection unit 2, a trigger sensor 8 is provided to detect a card takenin.

Different size cards K1, K2 and K3 are conveyed with one side held bythe front-side upper conveying belt 14 a and lower conveying belt 14 b,and conveyed with the other side held by the back-side upper conveyingbelt 14 c and lower conveying belt 14 d. In this time, the cards areconveyed with the center aligned with the center between the front-sideconveying belt 14 a/14 c and back-side conveying belt 14 b/14 d.

A front-side upper roller (a first roller) 15 a is provided between thefront-side upper conveying rollers 12 a and 12 b, and a back-side upperroller (a second roller) 15 a′ is provided between the back-side upperconveying rollers 12 a′ and 12 b′. A flange 15 f is provided in thefront-side upper roller 15 a, and a flange 15 f′ is provided in theback-side upper roller 15 a′. The flanges 15 f and 15 f′ of the upperrollers 15 a and 15 a′ constitute a first pressing unit.

A front-side lower roller (a third roller) 16 a is provided between thefront-side lower conveying rollers 13 a and 13 b, and a back-side lowerroller (a fourth roller) 16 a′ is provided between the back-side lowerconveying rollers 13 a′ and 13 b′. A flange 16 f is provided in thefront-side lower roller 16 a, and a flange 16 f′ is provided in theback-side lower roller 16 a′. The flanges 16 f and 16 f′ of the lowerrollers 16 a and 16 a′ constitute a second pressing unit.

The lower side of the flange 15 f/15 f′ of the upper roller 15 a/15 a′is projected downward the conveying path 11 by a predetermined amount,and the upper side of the flange 16 f/16 f′ of the lower roller 16 a/16a′ is projected upward the conveying path 11 by a predetermined amount.

The upper rollers 15 a and 15 a′ contact the upper side of the upperconveying belts 14 a and 14 c, and the lower rollers 16 a and 16 a′contacts the lower side of the lower conveying belts 14 c and 14 d. Theupper roller 15 a/15 a′ and lower roller 16 a/16 a′ are rotatedfollowing the conveying belts 14 a -14 d.

A linear light source 18 is provided as a light-emitting unit betweenthe lower conveying rollers 13 a/13 a′ and lower roller 16 a/16 a′ alongthe direction orthogonal to the card conveying direction. A linearlight-receiving sensor 19 is provided as a light receiver between theupper conveying roller 12 b/12 b′ and upper roller 15 a/15 a′ along thedirection orthogonal to the card conveying direction. The light emittedfrom the linear light source 18 is received by the light-receivingsensor 19.

The above-mentioned upper roller 15 a/15 a′ and lower roller 16 a/16 a′are moved by a moving mechanism 26 as shown in FIG. 3.

The upper rollers 15 a and 15 a′ are freely rotated taking the sleeves21 a and 21 a′ as a rotation axis. The lower rollers 16 a and 16 a′ arefreely rotated taking the sleeves 21 b and 21 b′ as a rotation axis.

The sleeves 21 a and 21 a′ are screwed into a shaft 17 a as a firstdrive shaft, and the sleeves 21 b and 21 b′ are screwed into a shaft 17b as a second drive shaft. The outer surfaces of the shaft 17 a and 17 bare formed with a male screw inversely and symmetrically with respect tothe centerline of the conveying path 11. The inner surfaces of thesleeves 21 a, 21 a′ and 21 b, 21 b′ are formed with a female screw toengage with the male screw of the shafts 17 a and 17 b.

The above-mentioned shafts 17 a and 17 b are provided along the cardconveying surface and in the direction orthogonal to the card conveyingdirection, and are arranged to move the upper roller 15 a/15 a′ andlower roller 16 a/16 a′ along the card conveying surface and in thedirection orthogonal to the card conveying direction.

When the above-mentioned shaft 17 a is rotated forward, the upperrollers 15 a and 15 a′ are moved together with the sleeves 21 a and 21a′ in the direction of coming close to each other, and the distancebetween the flanges 15 f and 15 f′ is narrowed.

When the shaft 17 b is rotated forward, the lower rollers 16 a and 16 a′are moved together with the sleeves 21 b and 21 b′ in the direction ofcoming close to each other, and the distance between the flanges 16 fand 16 f′ is narrowed.

When the shaft 17 a is rotated backward, the upper rollers 15 a and 15a′ are moved together with the sleeves 21 a and 21 a′ in the directionof separating from each other, and the distance between the flanges 15 fand 15 f′ is widened.

When the shaft 17 b is rotated backward, the lower rollers 16 a and 16a′ are moved together with the sleeves 21 b and 21 b′ in the directionof separating from each other, and the distance between the flanges 16 fand 16 f′ is widened.

Ends of the shaft 17 a and 17 b penetrate through a base 7, and areconnected through a toothed pulley 22 a, a toothed belt 23 and a toothedpulley 22 b constituting an interlock mechanism. One end of the shaft 17a is directly connected to a drive motor 24, which rotates forward andbackward. The shafts 17 a and 17 b are simultaneously rotated in theforward and backward directions by the forward/backward rotation of thedrive motor 24.

FIG. 5 is a block diagram of the control system of the paper sheetprocessing system.

In FIG. 5, a reference numeral 20 denotes a control unit. The controlunit 20 is connected with a trigger sensor 8 and a light-receivingsensor 19 through a transmission circuit. The control unit 20 controlsthe operation of the branch gate 3, based on detection signals sent fromthe trigger sensor 8 and light-receiving sensor 19.

Namely, the control unit 20 judges that a card has no break as shown inFIG. 8, based on the detection signal shown in FIG. 12 from thelight-receiving sensor 19. The control unit 20 judges that a card has abreak a as shown in FIG. 9, based on the detection signal shown in FIG.13 from the light-receiving sensor 19.

The control unit 20 operates the branch gate 3 to send a card K havingno break to the first stack 4, and send a card K having a break a to thesecond stack 5. A break in a card also includes defects in addition to asimple break.

Next, a description will be given on a method of detecting a break in acard.

A card K is conveyed with one side held by the front-side upperconveying belt 14 a and lower conveying belt 14 b, and conveyed with theother side held by the back-side upper conveying belt 14 c and lowerconveying belt 14 d, as shown in FIG. 6/FIG. 7 or FIG. 10/FIG. 11. Thecard K is detected by the trigger sensor 8, and one side is fed tobetween the front-side upper roller 15 a and lower roller 16 a, and theother side is fed to between the back-side upper roller 15 a′ and lowerroller 16′. In this time, one side of the card K is pushed upward by theflange 16 f of the front-side lower roller 16 a, the other side ispushed upward by the flange 16 f′ of the back-side lower roller 16 a′,one side of the card K is pushed downward by the flange 15 f of thefront-side upper roller 15 a, and the other side is pushed downward bythe flange 15 f′ of the back-side upper roller 15 a.

Therefore, the card K is deformed like a step viewed from the conveyingdirection, and passes through the light from the light source 18, justlike interrupting the light. In this time, when a predetermined darksignal as shown in FIG. 12 is output from the light-receiving sensor 19,the control unit 20 judges that the card K has no break. FIG. 6 and FIG.7 show the state that a card K. having no break is conveyed. Afterjudging that the card K has no break, the control unit 20 operates thebranch gate 3 to send the card K to the first stack 4. FIG. 12 shows asignal output when two cards having no break are continued.

On the other hand, when the light-receiving sensor 19 outputs adetection signal to output a light signal during a dark signal, as shownin FIG. 13, the control unit 20 judges that the card K has a break a.FIG. 10 and FIG. 11 show the state that the card K having a break isconveyed, and the break a is opened. After judging that the card K has abreak, the control unit 20 operates the branch gate 3 to send the card Kto the second stack 5. FIG. 13 shows a signal output when a card havinga break is conveyed subsequent to a card having no break.

As shown in FIG. 5, the control unit 20 is connected with an input unit25 through a transmission circuit, and is connected with a drive motor24, which rotates forward and backward through a control circuit. Whenhandling different size cards, the input unit 25 specifies the sizes ofthe cards. Based on the specified size information, the control unit 20controls the operation of the drive motor 24.

For example, when a small size is specified, the control unit 20 rotatesthe drive motor 24 forward and rotates the shaft 17 a forward.Therefore, the front-side upper roller 15 a and back-side upper roller15 a′ are moved in the direction of coming close to each other as shownin FIG. 14, and the distance between the flanges 15 f and 15 f′ isnarrowed.

In this time, the shaft 17 b is rotated forward through the toothedpulley 22 a, toothed belt 23 and toothed pulley 22 b. Therefore, thefront-side lower roller 16 a and back-side lower roller 16 a′ are movedin the direction of coming close to each other, and the distance betweenthe flanges 16 f and 16 f′ is narrowed.

Contrarily, when a large size is specified, the control unit 20 rotatesthe drive motor backward and rotates the shaft 17 a backward. Therefore,the front-side upper roller 15 a and back-side upper roller 15 a′ aremoved in the direction of separating from each other as shown in FIG.15, and the distance between the flanges 15 f and 15 f′ is widened.

In this time, the shaft 17 b is rotated backward through the toothedpulley 22 a, toothed belt 23 and toothed pulley 22 b. Therefore, thefront-side lower roller 16 a and back-side lower roller 16 a′ are movedin the direction of separating from each other, and the distance betweenthe flanges 16 f and 16 f′ is widened.

The light source 18 and light-receiving sensor 19 have a light-emittingwidth and a light-receiving width capable of covering the amount ofmovement of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′.

As described hereinbefore, the upper roller 15 a/15 a′ and lower roller16 a/16 a′ are moved in the direction of separating from each otherbased on the card size, and the flanges 15 f/15 f′ and 16 f/16 f′ can beset at the positions suitable for the card size, and a break in a cardcan be securely opened and detected.

When handling the same size card, the position to open a break in a cardcan be changed by changing the distance of the upper roller 15 a/15 a′and lower roller 16 a/16 a′ from the end-face of a card.

In this case, an operator inputs a desired amount of movement from theinput unit 25. Then, the control unit 20 controls the operation of thedrive motor 24, and the distance of flanges 15 f/15 f′ and 16 f/16 f′ ofthe upper roller 15 a/15 a′ and lower roller 16 a/16 a′ from theend-face of a card can be variably controlled.

For example, FIG. 16 shows the case that the break a in a card is openedby moving the flanges 15 f/15 f′ and 16 f/16 f′ of the upper roller 15a/15 a′ and lower roller 16 a/16 a′ from the end-face of a card to theinside by about 5 mm, and placing the flanges to the break. FIG. 17shows the case that the break a in a card is not opened by moving theflanges 15 f/15 f′ and 16 f/16 f′ of the upper roller 15 a/15 a′ andlower roller 16 a/16 a′ from the end-face of a card to the inside byabout 10 mm, and not placing the flanges to the break.

By adjusting the positions of the flanges 15 f/15 f′ and 16 f/16 f′ ofthe upper roller 15 a/15 a′ and lower roller 16 a/16 a′, it is possibleto detect only a break longer than a predetermined length withoutwastefully detecting a short break.

Further, in the embodiment described above, a card is conveyed along thelongish side. The conveying direction is not limited to this. A card maybe conveyed along the shorter side.

Embodiment 2

FIG. 18 and FIG. 19 show a detection unit according to a secondembodiment of the invention.

In the second embodiment, upper air nozzles 31 a/31 a′ and lower airnozzle 32 a/32 a′ are provided as first and second air nozzles and asthird and fourth air nozzles, instead of the flanges 15 f/15 f′ and 16f/16 f′ of the upper roller 15 a/15 a′ and lower roller 16 a/16 a′. Theupper air nozzles 31 a and 31 a′ are moved in the direction of comingclose to each other along the direction orthogonal to the card conveyingdirection, for example, according to the size of a card, as shown inFIG. 18. The lower air nozzles 32 a and 32 a′ are also moved in thedirection of coming close to each other, like the upper air nozzles 31 aand 31 a′.

The upper air nozzles 31 a and 31 a′ are moved in the direction ofseparating from each other along the direction orthogonal to the cardconveying direction, for example, according to the size of a card, asshown in FIG. 9. The lower air nozzles 32 a and 32 a′ are also moved inthe direction of separating from each other, like the upper air nozzles31 a and 31 a′.

Air ejected from the upper air nozzle 31 a/31 a′ and lower air nozzle 32a/32 a′ is blown to both sides of a card from the up/down direction,opens a break if any, and enables detection of a break.

The same effect as the first embodiment can be obtained from the secondembodiment.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1. A paper sheet break detection unit comprising: a conveying unit whichconveys a paper sheet along a conveying surface; a first pressing unitwhich presses one side of the paper sheet conveyed by the conveying unitin a first direction orthogonal to the conveying surface; a secondpressing unit which is provided in proximity to the first pressing unit,and presses the other side of the paper sheet conveyed by the conveyingunit in a second direction reverse to the first direction; alight-emitting unit which emits light to the paper sheet deformed by thepressure of the first and second pressing units; a light-receiving unitwhich receives the light illuminated from the light-emitting unit; ajudgment unit which judges whether the paper sheet includes a break,based on the reception of the light by the light-receiving unit; and amoving mechanism which moves the first and second pressing units alongthe conveying surface in a direction orthogonal to a direction ofconveying the paper sheet.
 2. The paper sheet break detection unitaccording to claim 1, wherein the conveying unit has a pair of firstconveying belts which holds and conveys one side of the paper sheet, anda pair of second conveying belts which is provided parallel to the firstconveying belt with a predetermined interval, and holds and conveys theother end of the paper sheet; the first pressing unit is composed of aflange of a first roller to contact the surface of one of the pair offirst conveying belts and rotate following the belts, and a flange of asecond roller to contact the surface of one of the pair of secondconveying belts and rotate following the belts; and the second pressingunit is composed of a flange of a third roller to contact the surface ofthe other of the pair of first conveying belts and rotate following thebelts, and a flange of a fourth roller to contact the surface of theother of the pair of second conveying belts and rotate following thebelts.
 3. The paper sheet break detection unit according to claim 2,wherein the moving mechanism has first and second drive shafts whichrotate forward and backward, and moves the flanges of the first andsecond rollers in a direction of coming close to each other by theforward rotation of the first drive shaft, moves the flanges of thethird and fourth rollers in a direction of coming close to each other bythe forward rotation of the second drive shaft, moves the flanges of thefirst and second rollers in a direction of separating from each other bythe backward rotation of the first drive shaft, and moves the flanges ofthe third and fourth rollers in a direction of separating from eachother by the backward rotation of the second drive shaft.
 4. The papersheet break detection unit according to claim 3, wherein the first andsecond drive shafts are interlocked through an interlock mechanism. 5.The paper sheet break detection unit according to claim 2, wherein theamount of movement of the flanges of the first and second rollers andthe flanges of the third and fourth rollers is controlled according tothe size of the paper sheet or the length of a break to be detected. 6.The paper sheet break detection unit according to claim 1, wherein thefirst pressing unit is composed of a first air nozzle to blow air to oneside of the paper sheet, and a second air nozzle to blow air to theother side of the paper sheet; and the second pressing unit is composedof a third air nozzle to blow air to one side of the paper sheet from adirection reverse to the first air nozzle, and a fourth air nozzle toblow air to the other side of the paper sheet from a direction reverseto the second air nozzle.
 7. The paper sheet break detection unitaccording to claim 6, wherein the first and second air nozzles are movedin a direction of coming close to or separating from each other, and thethird and fourth air nozzles are moved in a direction of coming close toor separating from each other.
 8. The paper sheet break detection unitaccording to claim 6, wherein the amount of movement of the first andsecond air nozzle and third and four air nozzles is controlled accordingto the size of the paper sheet or the length of a break to be detected.9. The paper sheet break detection unit according to claim 1, whereinthe paper sheet is rectangular, and conveyed along the longish side orshorter side.